Doris Huser’s memory of the Route 91 Harvest Festival in Las Vegas is a sickening blur, punctuated by perfect, still images: snapshots she will remember for the rest of her life. There is the image of the woman, her eyes vacant, lying on her back on the pavement in front of Huser: “I’ve been shot,” Huser recalled her saying. There is the woman whose wheel chair had tipped over in the panic after what would become the deadliest mass shooting in modern U.S.